• PANCREATIC CANCER

Pancreatic ductal adenocarcinoma (PDAC) is considered to be a highly aggressive and rapidly progressive disease by clinicians, which is one of the reasons why patients usually present at advanced stages of the disease and have a poor prognosis.1 In fact, this appears to be confirmed by the low number of small pancreatic cancers documented in population-based registries. Only 1.4% of 13 131 patients with pancreatic cancer in the SEER database (US National Cancer Institute's Surveillance, Epidemiology, and End Results) had tumours <1 cm, and even in these cases 30.1% had regional and 10.1% had distant metastases.2 These observations have been challenged by computational modelling of genome sequence data generated by comparative lesion sequencing of matched primary pancreatic cancers and distinct metastases of seven patients with end-stage pancreatic cancer.3 Yachida et al 3 predicted a long time interval of approximately 21 years from the initiating PDAC mutation until the patient's death,4 and estimated that pancreatic cancers remain confined to the pancreas for almost a decade, thus opening a broad window of opportunity to screen for preneoplastic lesions or early cancer.

Yu et al 2 present a study that was designed to estimate the time it takes for a pancreatic cancer to progress through different localised or locally advanced tumour stages. For this purpose, the authors analysed patient age, tumour size, stage and demographic information of 13 131 patients with pancreatic cancer registered in the SEER database over an extensive time period (2004–2011). The study is based on the hypothesis that the average time required for pancreatic cancers to progress through different tumour stages should be reflected in the average age of patients diagnosed at each stage of the disease. By comparing the mean age of patients with different tumour sizes at diagnosis, the authors conclude that disease progression is rapid, …